The act of falling in love with the pop singer Justin Bieber. This condition can affect anyone from the ages of 1 to 92.
You have Bieber fever if you have one or more of the following symptoms:
1. Your heart melts when you see his smile.
2. Your heart flutters when you hear him sing.

3. You think to yourself, "Aww he is the definition of innocence and perfection, he must be an angel."
4. You know the words to at least one of his songs.
5. You find yourself dancing to his music with people around or not.

6. You watch youtube videos of him all day long.
7. You own either My World, My World 2.0....or both.

8. You have bought tickets to his concert(thats an obvious one).
9. You are a 20 year old girl who has secret thoughts of getting with him.

10. You have given him a nickname, such as Biebs, Biebsta,or whatever else you have creatively come up with.

11. You cry because you want to meet him.

12. You think you and him are meant to be (aka marriage)

People....the list goes on and on. Basically you have Bieber fever if you have ANY positive thoughts about the guy.

The super-obsession of Justin Bieber and his songs; Knowing the words to all of Justin's songs and everything about him; The impression of having stayed up all night just listening to his songs and waking up in the morning feeling like you're sick.

The term Bieber fever applies mainly to prepubescent girls with a few exceptions. Most people that actually have bieber fever are either:
1. Deaf
2. Possesing an IQ below room temperature
3. Pedophiles
4. Knowing nothing about music
5. Under the age of 10

Few people know the cause of Bieber Fever, but it generally causes any girl years younger than him to love him and anyone with a tiny bit of manliness or sense of music having a strong hatred towards the girl they call Justin. Usually this would cause someone to go to jail and eventually get shanked multiple times, but Bieber is a celebrity and is known to attract miles of fools that can actually listen to his sqeaky xbox live-esque voice. After concerts, the crowds are generally worse than riots, and the Local Swat teams have to hold back the now savage fans.

Dumbass Girl: Woo! I have Bieber Fever!

Person with complexity above a fruit fly: He makes horrible music, how can you like him?